The invention relates to a franking machine with an electronic control unit for the control of a device for setting franking values on its printing head and an input keyboard for inputting weight values or weight ranges, the control unit having a computer and a memory (PROM) for postage rates, so that the weight inputs are converted into franking values for the automatic setting of the printing head by the computer.
A franking machine of this type is described in EP-A-387 202. For franking value setting on the basis of a weight input, the electronic device enclosed in the sealed casing is equipped with a memory containing the postage rates. Therefore in the case of such a franking machine there is no need to input the franking values by means of a keyboard and it is sufficient in place of this to merely input by means of the keyboard the weight or the weight step (up to 20 g, up to 50 g, up to 100 g, etc.) or to connect an external, electronic balance.
When the postage rates are changed, i.e. when the relationship between the rate and the franking value is modified, it is necessary to call in an authorized fitter and, by opening the lead-sealed casing, to replace the postage rate memory by a new one.